Pity it's not a genuine note (5)
I believe the answer is:
shame
'pity' is the definition.
(I know that pity can be written as shame)
'it's not a genuine note' is the wordplay.
'it' becomes 'sa' (SA can mean sex appeal, as in 'it').
'not' suggests deleting specific letters.
'genuine' becomes 'ham' (I can't explain this - if you can you should give a lot more credence to this answer).
'note' becomes 'e' (musical note).
'sa' with 'a' taken away is 's'.
's'+'ham'+'e'='SHAME'
Can you help me to learn more?
(Other definitions for shame that I've seen before include "Humiliation; dishonour" , "Painful emotion resulting from guilt" , "Feeling of humiliation" , "scandal" , "Disgrace - Salman Rushdie novel" .)